Digital I/O Pins:
• 14 digital pins
○ 6 support PWM output (D3, D5, D6, D9, D10, D11)

Analog Input Pins:
• 6 analog inputs (A0–A5)

DC Current per I/O Pin:
• 20 mA

DC Current for 3.3V Pin:
• 50 mA

Flash Memory:
• 32 KB (0.5 KB used by bootloader on some clones)

SRAM:
• 2 KB

EEPROM:
• 1 KB

Clock Speed:
• 16 MHz

USB Controller:
• CH340G (common in compatible boards)
○ Requires driver installation on Windows

Communication:
• UART
• I2C
• SPI

Power Jack:
• DC barrel jack

USB Port:
• USB Type-B or USB-A to USB-B cable

Reset Button:
• Yes

Dimensions:
• 68.6 mm × 53.4 mm

Weight:
• ~25 g